4-Hydroxybenzocyclobutene, has been prepared by diazotization and heating of the corresponding amine, Horner et al., Chem. Ber., vol. 93 (1960), pages 1774-1781. The yield of 4-hydroxybenzocyclobutene is about 50%.
So, in the U.S. Pat. No. 4,570,011, has proposed the synthesis of hydroxybenzocyclobutenes by pyrolysis of a chloromethyl methylbenzoate precursor.
Paparatto, in U.S. Pat. No. 4,684,749, has proposed, converting iodobenzene to phenol in the presence of a basic acidity acceptor in the liquid phase, in the presence of a copper-containing catalyst. The acidity acceptor can be NaOH or KOH. A methanol/water solvent system gave 64% conversion of iodobenzene, with a selectivity to phenol of 50% and a selectivity to anisole of 47%. Use of an aqueous toluene solvent system gave significantly higher selectivity toward phenol.
Hale, in U.S. Pat. No. 2,028,055, has proposed simultaneous hydrolysis and ammonolysis of aryl halides at temperatures from 150.degree. C. to 260.degree. C., preferably at 200.degree.-240.degree. C. The catalyst comprises a cuprous, silver, cobaltic or zinc compound.
Hale, in U.S. Pat. No. 1,882,824, has also proposed converting chlorobenzene to phenol by reaction with sodium carbonate in the presence of copper metal at 250.degree.-375.degree. C.
Smith et al., in U.S. Pat. No. 4,001,340, have recited hydrolyzing haloaromatic compounds by concentrated aqueous hydroxide solutions at 250.degree.-330.degree. C. A copper catalyst is used.
Poffenberger, in U.S. Pat. No. 2,137,587, teaches preparation of phenol by hydrolysis of chlorobenzene with excess sodium hydroxide solution at 350.degree.-400.degree. C. under pressure.
It is the object of this invention to provide highly selective, high yield, low temperature processes for the preparation of hydroxybenzocyclobutene compounds so as to prevent premature oligomerization or polymerization of resulting hydroxy-benzocycobutene products.